A patient with long-standing chronic obstructive pulmonary disease presents to the emergency department with increased cough and difficulty breathing. The following arterial blood gas analysis is...

A patient with long-standing chronic obstructive pulmonary disease presents to the emergency department with increased cough and difficulty breathing. The following arterial blood gas analysis is obtained: pH 7.34, PaO2 76 mm Hg, PaCO2 60, [HCO₃
^-] 28.Which of the following is the primary acid-base disturbance and its compensatory mechanism?

A. Respiratory acidosis with a compensatory metabolic alkalosis

B. Metabolic acidosis with a compensatory respiratory alkalosis

C. Respiratory alkalosis with a compensatory metabolic acidosis

D. Metabolic alkalosis with a compensatory respiratory acidosis

E. None of the above